A typical hinge connects two objects, allowing a limited range of angular rotation about a fixed axis between the objects. Typically, a hinge does not lock in a position. Thus, the objects may be freely moved from one angular position to another angular position.
Various locking hinges have been devised. For example, hinges for folding ladders include a ratcheting mechanism to lock the hinge in a position. A releasable spring actuated pawl engages a toothed cog. The engaged pawl prevents rotation. To release the pawl a lever must be raised or pressed while pressure is relieved. Relieving pressure typically entails manipulating the hinged objects so that the pawl is between adjacent teeth, without considerable stress against either tooth. While such a mechanism is useful for a ladder that will be opened and closed by skilled adults, it is not well suited for a device that may be used by children.
Other locking mechanisms including latches, bolts and stops that may be positioned to prevent angular rotation. Such mechanisms are useful, but are separate from the hinge.
What is needed is a hinge that can be used in a wide variety of applications, including children's furniture. The hinge should lock into an open position. When locked, the hinge should resist closing during normal use of the object (e.g., furniture). The hinge should unlock by pivoting one particular side. Thus, by folding the object (e.g., furniture) in the correct sequence, unlocking is achieved.
The invention is directed to overcoming one or more of the problems and solving one or more of the needs as set forth above.